Abnormality detecting system for a solar power grid

Abstract

A system is provided to be disposed between a solar power module and a power inverter. The solar power module outputs a solar power signal to the power inverter. The system includes a circuit protecting unit and a processor. The processor obtains an amount of electrical current outputted by the power inverter and an amount of electrical current flowing through a current detector of the circuit protecting unit. When it is determined that the amount of electrical current outputted by the power inverter is zero and the amount of the electrical current flowing through the current detector is non-zero, the processor controls a power switch of the circuit protecting unit to switch to an open circuit state.

What is claimed is: 
     
       1. An abnormality detecting system for a solar power grid, the solar power grid including at least one power inverter and at least one solar power module, each of the at least one power inverter having a first receiving node and a second receiving node, the abnormality detecting system being disposed between the at least one solar power module and the at least one power inverter, each of the at least one solar power module including at least one solar panel, and both a first output node and a second output node cooperatively outputting a solar power signal formed as a direct current signal, the second receiving node of the at least one power inverter being electrically connected to the second output node of a corresponding one of the at least one solar power module, the at least one power inverter being electrically connected to the at least one solar power module to receive the solar power signal therefrom and being configured to convert the solar power signal into a converted power signal formed as an alternating current (AC) signal and output the converted power signal, and the abnormality detecting system, comprising:
 at least one circuit protecting unit, each circuit protecting unit including:
 an input component including a first port and a second port, the first and second ports being electrically connected, respectively, to the first output node and the second output node of the corresponding one of the at least one solar power module, and thereby the input component receiving the solar power signal through said first and second ports; 
 a power switch electrically connected to said first port of said input component; 
 an output component electrically connected between said power switch and the power inverter, wherein said output component is electrically connected to the first receiving node of a corresponding one of the at least one power inverter; 
 a current detector electrically connected between said input component and said output component, wherein said current detector and said power switch are electrically connected in series to be together positioned between said first port of said input component and said output component, and the current detector being configured to measure electrical current flowing therethrough; and 
 a control module electrically connected to said current detector and said power switch, said control module controlling said power switch to switch between an open circuit state and a closed circuit state, wherein in the open circuit state, electrical current is not flowable through said power switch, and wherein in the closed circuit state, electrical current is flowable through said power switch; 
 a power supply module electrically connected between said input component and said control module, said power supply module supplying power to said control module according to the solar power signal; and 
 a processor electrically connected to said control module and the at least one power inverter, and the processor being configured to acquire a magnitude of electrical current of the converted power signal output by the at least one power inverter; 
 
 wherein when said power switch is in the closed circuit state, the processor is configured to actuate the control module to obtain a magnitude of electrical current flowing through said current detector; and 
 wherein when it is determined that the magnitude of electrical current of the converted power signal is zero and the magnitude of the electrical current flowing through said current detector is non-zero, the processor is configured to, responsively, actuate said control module to switch said power switch to the open circuit state; and 
 wherein when the abnormality detecting system is disposed between a plurality of solar power modules and a plurality of power inverters, each of a plurality of said circuit protecting units is electrically connected to a respective one of the solar power modules, to a respective one of the power inverters, and to said processor, each of the plurality of power inverters measures an input impedance with respect to that particular power inverter, and responsive to the at least one power inverter determining that the input impedance of that particular power inverter is different from an associated normal value, the particular power inverter transmits an error signal to said processor and shuts down, and said processor is configured to operate in a troubleshooting mode responsive to receiving the error signal from the particular power inverter, wherein, in the troubleshooting mode, said processor's operations include the following:
 actuate said control module to switch said power switch to the open circuit state for each of said circuit protecting units connected to a corresponding one of the power inverters; 
 conduct a test procedure upon a determination being made with respect to the particular power inverter that the input impedance thereof is no longer different from the associated normal value, the test procedure includes said processor controlling, one by one, said control module(s), respectively, of said circuit protecting unit(s), connected to a corresponding one of the power inverters, to switch said corresponding power switch thereof to the closed circuit state for a predetermined time period; and 
 determine, for each of said circuit protecting units connected to one of the power inverters, in turn, whether a component of the solar power grid connected to said power switch is functional based on whether the error signal is received from one of the at least one power inverter. 
 
 
     
     
       2. The abnormality detecting system of  claim 1 , wherein said processor is further configured to:
 receive a voltage value of the solar power signal from the at least one power inverter; 
 compare the voltage value of the solar power signal with a predetermined voltage value; and 
 generate an alert when the voltage value of the solar power signal is lower than the predetermined voltage value. 
 
     
     
       3. The abnormality detecting system of  claim 1 , further comprising a manual kill switch that is electrically connected to said processor and that generates a shutdown signal and transmits the shutdown signal to said processor upon manual operation,
 wherein in response to receipt of the shutdown signal from said manual kill switch, said processor controls said control module to control said power switch to switch to the open circuit state. 
 
     
     
       4. The abnormality detecting system of  claim 1 , further comprising a temperature sensor that is electrically connected to said processor and that is configured to periodically generate a reading of ambient temperature, wherein:
 said processor is configured to periodically obtain one reading of the ambient temperature, and when it is determined that each of a number of successive readings of said temperature sensor is higher than a predetermined threshold, said processor controls said control module to control said power switch to switch to the open circuit state. 
 
     
     
       5. The abnormality detecting system of  claim 1 , wherein when the plurality of said circuit protecting units are each configured to be electrically connected to a respective one of the solar power modules, the at least one power inverter, and said processor, further comprising:
 in response to a manual setup operation, said processor is configured to operate in a reset mode wherein said processor periodically controls said control modules respectively of said circuit protecting units to control said power switches, respectively, of said circuit protecting units to switch to the open circuit state for a predetermined time period. 
 
     
     
       6. The abnormality detecting system of  claim 1 , wherein during the troubleshooting mode, said processor is further configured to:
 control, in response to a determination that no error signal is received when a corresponding one of said power switches is in the closed circuit state, a control module of another one of said circuit protection units to switch said power switch thereof to the closed circuit state, after implementation of the troubleshooting mode. 
 
     
     
       7. The abnormality detecting system of  claim 1 , wherein said power switch includes one of a silicon controlled rectifier (SCR), an insulated gate bipolar transistor (IGBT), or a metal-oxide-semiconductor field-effect transistor (MOSFET). 
     
     
       8. An abnormality detecting system for a solar power grid, the solar power grid including at least one power inverter and at least one solar power module, each of the at least one power inverter having a first receiving node and a second receiving node, the abnormality detecting system being disposed between the at least one solar power module and the at least one power inverter, each of the at least one solar power module including at least one solar panel, and both a first output node and a second output node cooperatively outputting a solar power signal formed as a direct current signal, the at least one power inverter being electrically connected to a corresponding one of the at least one solar power module to receive the solar power signal therefrom and being configured to convert the solar power signal to a converted power signal formed as an alternating current (AC) signal and output the converted power signal, and the abnormality detecting system, comprising:
 an external power supply; 
 at least one circuit protecting unit, each circuit protecting unit including: 
 an input component including a first port and a second port, the first and second ports being electrically connected, respectively, to the first output node and the second output node of the corresponding one of the at least one solar power module, and thereby the input component receiving the solar power signal through said first and second ports; 
 a power switch electrically connected to said first port of said input component; 
 an output component electrically connected between said power switch and the at least one power inverter, said output component including a first output port and a second output port, respectively, electrically connected to the first receiving node and the second receiving node of a corresponding one of the at least one power inverter, wherein the first output port of said output component is also electrically connected to said power switch; 
 a current detector electrically connected between said input component and said output component, wherein the second output port of said output component is also electrically connected to said current detector, and the current detector being configured to measure electrical current flowing therethrough; 
 a control module electrically connected to said current detector and said power switch, said control module controlling said power switch to switch between an open circuit state and a closed circuit, wherein in the open circuit state, electrical current is not flowable through said power switch, and wherein in the closed circuit state, electrical current is flowable through said power switch; 
 a power unit electrically connected to said control module, and a kill switch electrically connected between said power unit and said external power supply, and said kill switch being configured to switch between a conductive state and a non-conductive state, wherein in the conductive state, said control module is powered by the external power supply, and wherein in the non-conductive state, said control module does not receive power from the external power supply; and 
 a processor electrically connected to said control module and the at least one power inverter, and the processor being configured to obtain a magnitude of electrical current of the converted power signal output by the at least one power inverter; 
 wherein when said power switch is in the closed circuit state, the processor is configured to actuate the control module to obtain a magnitude of electrical current flowing through said current detector; 
 wherein when it is determined that the magnitude of electrical current of the converted power signal is zero and the magnitude of the electrical current flowing through said current detector is non-zero, the processor is configured to responsively actuate said control module to switch said power switch to the open circuit state; 
 wherein when the abnormality detecting system is disposed between a plurality of solar power modules and a plurality of power inverters, each of a plurality of said circuit protecting units is electrically connected to a respective one of the solar power modules, a respective one of the power inverters, said processor, and said external power supply, wherein each of the plurality of power inverters measures an input impedance with respect to that particular power inverter, and responsive to the particular power inverter determining that the input impedance is different from an associated normal value, the power inverter transmits an error signal to said processor and shuts down, and wherein said processor operates in a troubleshooting mode responsive to receiving the error signal from at least one of the power inverters, wherein, in the troubleshooting mode, said processor's operations include the following:
 actuate said control module to switch said power switch to the open circuit state for each of said circuit protecting units connected to a corresponding one of the power inverters; 
 conduct a test procedure upon a determination being made that one of the power inverters has become operational, the test procedure includes said processor controlling, one by one, said control module(s), respectively, of said circuit protecting unit(s) connected to a corresponding one of the power inverters to switch said corresponding power switch thereof to the closed circuit state for a predetermined time period; and 
 determine, for each of said circuit protecting units connected to a corresponding one of the power inverters, in turn, whether a component of the solar power grid connected to said power switch is functional based on whether the error signal is received from one of the at least one power inverter. 
 
 
     
     
       9. The abnormality detecting system of  claim 8 , wherein said processor is further configured to:
 receive a voltage value of the solar power signal from the at least one power inverter; 
 compare the voltage value of the solar power signal with a predetermined voltage value; and 
 generate an alert when the voltage value of the solar power signal is lower than the predetermined voltage value. 
 
     
     
       10. The abnormality detecting system of  claim 8 , further comprising a manual kill switch electrically connected between said power unit and said external power supply, and said kill switch being configured to operate in either one of a conductive state or in a non-conductive state responsive to manual operation thereof;
 wherein in the conductive state of said manual kill switch, electrical current flows between said external power supply and said power unit to thereby power said control module, and wherein in the non-conductive state of said manual kill switch, electrical current does not flow through said power unit and thereby said control module is not powered. 
 
     
     
       11. The abnormality detecting system of  claim 8 , further comprising a temperature sensor that is electrically connected to said processor and that is configured to periodically generate a reading of ambient temperature, wherein:
 said processor is configured to periodically obtain one reading of the ambient temperature, and when it is determined that each of a number of successive readings of said temperature sensor is higher than a predetermined threshold, said processor controls said control module to control said power switch to switch to the open circuit state. 
 
     
     
       12. The abnormality detecting system of  claim 8 , wherein when the plurality of said circuit protecting units are each configured to be electrically connected to a respective one of the solar power modules, the at least one power inverter, and said processor, further comprising:
 said processor is configured to operate in a reset mode, wherein said processor periodically controls said control modules, respectively, of said circuit protecting units to control said power switches, respectively, of said circuit protecting units to switch to the open circuit state for a predetermined time period. 
 
     
     
       13. The abnormality detecting system of  claim 8 , wherein during the troubleshooting mode, said processor is further configured to:
 control, in response to a determination that no error signal is received when a corresponding one of said power switches is in the closed circuit state, a control module of another one of said circuit protection units to switch said power switch thereof to the closed circuit state, after implementation of the troubleshooting mode. 
 
     
     
       14. The abnormality detecting system of  claim 8 , wherein said power switch includes one of a silicon controlled rectifier (SCR), an insulated gate bipolar transistor (IGBT), or a metal-oxide-semiconductor field-effect transistor (MOSFET).